Keizer weather in September

In September, Keizer sees average daytime highs of 77°F and overnight lows near 53°F, with 1.2 in of rain across 4.8 wet days and about 12.3 hours of daylight. It is the 3rd-warmest and 9th-wettest month of the year here.

Highs ease over the month, from about 80°F in the first days to 73°F by the end. The sky is clear or mostly clear about 52% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 06 min at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Keizer's 3rd-clearest and 10th-windiest month. For the whole year in context, see Keizer's year-round climate.

Daytime high
77°
3rd warmest
Overnight low
53°
10th coldest
Rainfall
1.2 in
4.8 wet days
Daylight
12 h 18 min
5:57 AM – 6:16 PM
Cloud cover
40%
3rd clearest
Wind
5 mph
10th windiest
Solar energy
4.62 kWh/m²
Travel score
7.9
out of 10

Keizer is city in Oregon, USA.

Density
2,030/km²
people per km²
Founded
1982

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 80°F in the first days to 73°F by the end.

A typical September day in Keizer reaches about 77°F in the afternoon and slips back to 53°F overnight — a 24°F spread between the day's warmth and the night's chill. On most days the high lands between 66°F and 88°F. Set against its neighbours, September runs about 7°F cooler than August and about 12°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
18155
28155
38055
48055
58055
68055
78055
87955
97954
107954
117854
127854
137854
147753
157753
167753
177653
187653
197653
207652
217552
227552
237452
247451
257451
267351
277351
287350
297250
307250

How September really feels in Keizer

Once humidity and wind are folded in, September averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Keizer weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan48° / 37°6.115.90.791.5
Feb52° / 38°4.613.70.810.12.3
Mar56° / 40°5.115.70.411.63.2
Apr61° / 43°3.614.3013.24.3
May68° / 48°2.29014.66.3
Jun74° / 53°1.25.9015.47.4
Jul83° / 57°0.31.9015.17.3
Aug83° / 57°0.42013.97.2
Sep77° / 53°1.24.8012.37.9
Oct64° / 46°3.410.3010.75.7
Nov53° / 41°6.015.90.19.32.6
Dec47° / 37°7.116.80.68.61.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 52% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 13% of September, with mostly cloudy or overcast conditions the remaining 35%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17228
27129
37030
47030
56931
66832
76733
86733
96535
106436
116337
126238
136238
146139
156139
166238
176139
186238
196238
206238
216337
226337
236436
246436
256436
266436
276535
286436
296436
306337

Chance of precipitation in September

Any precipitation

Keizer gets around 1.2 in of rain over 4.8 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 17% and peaks near 23% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%151015202530
Rain chance (%)
110
211
311
412
512
613
713
814
915
1016
1116
1217
1317
1418
1518
1618
1718
1818
1918
2019
2119
2219
2319
2419
2520
2620
2720
2821
2922
3023

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the dry band about 85% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
182180
282180
383170
483170
583170
683170
784160
883161
983161
1083161
1183161
1283161
1383161
1484151
1584151
1684151
1785141
1885141
1986131
2086131
2186122
2286122
2387112
2487112
2588102
2688102
279091
289091
299091
309181

Wind in September

Winds average 5 mph in September.

Across September, daily wind ranges from about 5 mph on the calmest days to 5 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (mph)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 06 min at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 90 minutes over September. Sunrise moves from 5:39 AM to 6:15 AM, and sunset from 6:45 PM to 5:48 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.15:396:45
213.15:406:43
313.05:416:41
412.95:426:39
512.95:446:37
612.85:456:35
712.85:466:33
812.75:476:31
912.75:496:30
1012.65:506:28
1112.65:516:26
1212.55:526:24
1312.55:536:22
1412.45:556:20
1512.45:566:18
1612.35:576:16
1712.35:586:14
1812.26:006:12
1912.16:016:10
2012.16:026:08
2112.06:036:06
2212.06:056:04
2311.96:066:02
2411.96:076:00
2511.86:085:58
2611.86:105:56
2711.76:115:54
2811.76:125:52
2911.66:135:50
3011.66:155:48

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.62 kWh/m².

For context, solar energy here swings from a low near 1.08 kWh/m² to a high of 7.04 kWh/m² in July across the year — September's 4.62 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.4Bright
25.3Bright
35.3Bright
45.3Bright
55.2Bright
65.1Bright
75.1Bright
85.0Bright
95.0Bright
104.9Bright
114.8Bright
124.8Bright
134.7Bright
144.7Bright
154.6Bright
164.5Bright
174.5Bright
184.4Bright
194.4Bright
204.3Bright
214.3Bright
224.2Bright
234.2Bright
244.1Bright
254.0Bright
264.0Moderate
273.9Moderate
283.9Moderate
293.8Moderate
303.7Moderate
Planning a trip in September

Hazard calendar for Keizer

In seasonPeak

None of Keizer's seasonal hazards are active in September. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Keizer's rainy season runs October–April, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Keizer?

Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

7.9
Sightseeing
1st-best month of the year
6.9
Beach & pool
3rd-best month of the year

September is one of the better times to visit Keizer for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Keizer in September

From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In September, Keizer sees daytime highs around 77°F and nights near 53°F. Worth packing: light clothes and sun protection. About 5 days see rain.

light clothessun protection

UV index in Keizer in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Keizer peaks around July 17 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateVery highHighModerateLowJul 17UV 8Dec 17UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar4Moderate
Apr5High
May8Very high
Jun7High
Jul8Very high
Aug7Very high
Sep5Moderate
Oct4Moderate
Nov1Low
Dec1Low

Air quality in Keizer in September

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.

Air quality in Keizer is worst in September — around 34 µg/m³ PM2.5 (moderate), about 5.1× the cleanest month (January, 7 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

010203040JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1531 µg/m³Jan 167 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb8Good
Mar11Good
Apr11Good
May9Good
Jun8Good
Jul7Good
Aug14Moderate
Sep34Moderate
Oct11Good
Nov10Good
Dec8Good
Location & terrain

Where is Keizer?

Keizer sits at 45.0°N, 123.0°W, 138 ft above sea level, in United States. The nearest listed city is Hayesville, 1.9 mi away.

Topography around Keizer

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Keizer.

Within 2 miles, the terrain around Keizer has only modest variations in elevation — a maximum elevation change of 108 ft around an average of 144 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,079 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 5,492 ft.

The land around Keizer is covered by trees (39%) and artificial surfaces (36%) within 2 miles, trees (37%), cropland (31%) and grassland (21%) within 10 miles, and trees (71%) within 50 miles.

2 miles
108 ft
10 miles
1,079 ft
50 miles
5,492 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Hayesville 1.9 mi · Salem 3.1 mi · Four Corners 5.0 mi · Woodburn 14 mi · Dallas 15 mi · McMinnville 17 mi · Newberg 22 mi · Wilsonville 25 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Keizer (44.9901°, -123.0262°, elevation 138 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).